Abstract: An on-board charger system, and a method and a device for controlling the on-board charger system to switch between operating modes are provided. An operating mode switching signal for the on-board charger system is acquired. A to-be-started power module in the on-board charger system is controlled, based on the operating mode switching signal, to start in a current source mode and adapt a given current to an operating condition until a power demand of the system is met. The to-be-started power module is switched to a voltage source mode, and controls the voltage across the direct current bus. Throughout the switch, a voltage across a direct current bus in the system remains unchanged.

Abstract: An energy conversion system, and a method and a device for controlling the energy conversion system at an overtemperature are provided. The energy conversion system includes at least one power conversion circuit each including at least two power modules that are cascaded. Respective operating temperatures of all the power modules are measured in real time, to determine the overheated power module that is operating at an overtemperature and the underheated power module that is operating at a normal temperature. Once an overheated power module is detected, a decreased power and a power difference for the overheated power module are acquired, and an increased power for the underheated power module is determined based on the power difference. The operating power of the overheated power module is decreased at the module level with the total operating power of the system remains constant or approximately constant.

Abstract: A cascaded power electronic transformer and a method for controlling the same are provided. The method includes: calculating electrical angles ?i1 and ?kps of an sth transformer and a compensation electrical angle ?j of a jth transformer; adding the compensation electrical angle ?j to the electrical angle ?kps of the jth transformer, to obtain a compensated electrical angle ?kps of the jth transformer; and calculating a square wave of a bridge arm voltage of each of the m primary converters and the r secondary converters of the sth transformer based on the electrical angle ?i1 and the electrical angle ?kps of the sth transformer after compensation.

Abstract: A threading sealing box includes a box body and a threading assembly, and an opening is formed in the box body, a mounting groove is formed in a side wall of the box body, the threading assembly comprises a threading plate assembly and a threading body, the threading plate assembly is slidably arranged in the mounting groove so as to slide into or slide out of the mounting groove, a penetrating hole is formed in the threading plate assembly, the threading body is arranged on the threading plate assembly, and the threading body communicates with the penetrating hole. A cable penetrating through the threading body can be circumferentially sealed by the threading body, thereby effectively reducing the water leakage risk; the cable does not need to be locked by using accessories such as a waterproof terminal, such that the operation is simple.

Abstract: An inverter module and an inverter are provided. The inverter module includes at least two capacitors and at least one power unit group. The at least one power unit group each comprises one or more power units. The capacitors are connected in series and parallel to form a capacitor head terminal, a capacitor end terminal and a capacitor midpoint, where capacitance between the capacitor midpoint and the capacitor head terminal is the same as capacitance between the capacitor midpoint and the capacitor end terminal. Positive poles of DC sides of the power units are equidistantly connected with the capacitor head terminal, negative poles of the DC sides of the power units are equidistantly connected with the capacitor end terminal, and midpoints of the DC sides of the power units are equidistantly connected with the capacitor midpoint.

Abstract: A method for component voltage limitation, and an apparatus and a system for applying the same. At least one photovoltaic cell in a photovoltaic-cell string is controlled to operate in a voltage-limited mode, in response to receiving an instruction for enabling voltage limitation. Thereby, the voltage of the photovoltaic-cell string is reduced. A quantity of photovoltaic modules connected in series can be increased, while a highest voltage of the system is guaranteed not to exceed a corresponding requirement. A system cost is reduced. The photovoltaic cell operating in the voltage-limited mode is controlled to resume a normal output, in response to receiving the instruction for suspending voltage limitation. The output voltage of the photovoltaic-cell string is increased. Thereby, a rate of utilization on a direct voltage, and a PVIR of DC/AC are improved for the photovoltaic system.

Abstract: A radiator and an electrical device. The radiator includes a heat dissipation substrate and a heat dissipation assembly, wherein the heat dissipation substrate is provided with an installation position for installing the heat dissipation assembly, the installation position is provided with a stress release groove, and the heat dissipation assembly is welded on the installation position. According to the radiator provided in the present application, the stress release groove is provided in the installation position for installing the heat dissipation assembly on the heat dissipation substrate, such that the installation position is isolated from the connecting position of the heat dissipation assembly to form an island structure, and the island structure reduces stress pulling caused by thermal deformation of the two materials of the heat dissipation assembly and the radiator.

Abstract: A heat exchanger includes a heat exchange core arranged inside the housing, and a side of the housing is provided with an air vent. The heat exchanger is provided with a communication channel in communication with the air vent. The communication channel is located inside the housing, and is located at a side in the housing opposite to the air vent. In the heat exchanger, the air vent is in communication with the communication channel inside the housing, and the communication channel is located at the side in the housing opposite to the air vent, such that the internal space of the housing is fully utilized. Compared to the prior art, the overall size of the heat exchanger is reduced, and the cost for the heat exchanger is reduced.

Abstract: A mounting piece of the case includes a case connecting outer wall and a cover plate connecting outer wall, wherein the case connecting outer wall is provided with a through hole allowing for a case fixing part on an inner wall of a case body to pass through. The provision of the through hole in the mounting piece of the case to allow the case fixing part on the inner wall of the case body to pass through enables the case fixing part to be directly fixed to the case body, without providing a hole in the case body, such that waterproofing can be achieved without providing a seal between the mounting piece and the case body, thus effectively reducing installation materials and improving installation efficiency.

Abstract: Provided are a method for controlling operation of a module level power electronics (MLPE) device, a method for controlling MLPE devices and a photovoltaic system. In the method for controlling operation of a MLPE device, if it is determined that a current of a photovoltaic string where the MLPE device is located is less than a current threshold and coding information sent by a converter in the photovoltaic system is not received for a first preset time period, an output voltage or an output power of the MLPE device is controlled to be less than a corresponding threshold.

Abstract: An inverter and a method for identifying a fault on an alternating current side of a photovoltaic system are provided. A controller records a waveform of a preset parameter of the photovoltaic system, and then transmits the recorded waveform to an external device. The external device that performs relatively excellently in data storage and processing stores the waveform and performs subsequent processing, to accurately recognize the fault on the alternating current side of the inverter. Further, the fine waveform can be seen from the external device, so that the accuracy of system monitoring is greatly improved. Moreover, the external device analyzes the waveform and generates a control instruction to accurately control the inverter due to advantages of storage capacity, big data, and computing power. In addition, system performance can be optimized in cooperation with a local control unit.

Abstract: A connector for a case shell of a power apparatus includes a main body member. Two ends of the main body member are respectively connected to different members of the case shell, and the main body member is deformable; and the main body member is used to deform when an explosion occurs inside the case shell and the different members of the case shell connected by means of the main body member are disengaged from each other. The main body member of the connector can deform when devices inside the case shell explode and the different members of the case shell connected by means of the main body member are disengaged from each other, such that two members of the case shell connected by means of the main body member are slightly disengaged from each other to form a gap.

Abstract: An electrical apparatus is provided. The electrical apparatus includes: a box, an external device, fixed to an outer side of the box; and an external handle, arranged on the external device, wherein the external handle is configured for carrying of the electrical apparatus.

Abstract: A rapid shutdown system and a method for controlling the rapid shutdown system are provided. For each of shutdown devices in the rapid shutdown system, an electrical signal disturbance is applied to a direct current bus connected to the shutdown device at least once within each pre-shutdown period of the shutdown device, by an inverter in the rapid shutdown system operating in a mode of limited power output. Then, the shutdown device samples its input parameter and/or output parameter and determines, based on the sampled input parameter and/or the sampled output parameter, whether the electrical signal disturbance applied to the direct current bus meets a preset condition. The shutdown device switches itself on or remains in an ON state in response to a determination result that the electrical-signal disturbance already meets the preset condition.

Abstract: A method for switching between a forward operation and a reverse operation of an isolated bidirectional DC-DC circuit, a controller, a bidirectional converter, and a charging system are provided. The method includes: on receiving a switching signal, controlling a second bridge arm circuit to stop synchronous rectification, and adjusting phases of driving signals of two bridge arm branches in the first bridge arm circuit; in a case that the output current of the second bridge arm circuit reaches a first predetermined current, controlling the first bridge arm circuit to stop operating, and adjusting phases of driving signals of two bridge arm branches in the second bridge arm circuit; and in a case that the output current of the second bridge arm circuit reaches a second predetermined current, controlling the first bridge arm circuit to resume operating and perform synchronous rectification.

Abstract: A charging pile, a power module, and a method for controlling the same. In response to receiving a signal of operation, samples of an input voltage of three relays corresponding to three phases, respectively, at an input of a power module are acquired to determine whether a line voltage between inputs of two of the three relays is within a predetermined voltage range. The two relays are closed to pre-charge a bus capacitor in a converting circuitry of the power module, in response to determining that the line voltage is within the predetermined voltage range. The predetermined voltage range comprises zero voltage, such that each relay can be closed when a voltage at its input is close to zero. An impulse current is decreased without help of an arc quenching device, thereby saving an internal space of the charging pile.

Abstract: A photovoltaic inverter is provided. The photovoltaic inverter includes a cabinet and a power module arranged in the cabinet. The power module includes an inverter power unit, a first ventilating passage and a second ventilating passage isolated from the first ventilating passage. The inverter power unit is arranged upstream of the first ventilating passage in a direction in which air is inputted. The first ventilating passage is provided with a first air inlet and a first air outlet. The second ventilating passage is provided with a second air inlet and a second air outlet. In the photovoltaic inverter according to the present disclosure, the inverter power unit that heats up severely is provided with an independent ventilating passage for heat dissipation. In addition, the inverter power unit is arranged the upstream of the first ventilating passage in the direction in which air flows.

Abstract: An isolated bidirectional converter and a method for controlling the same are provided. A primary winding or a secondary winding of a transformer module in the isolated bidirectional converter is connected in parallel with a first branch includes a first inductor and a first current sensor that are connected in series. A current flowing through the first inductor is acquired by the first current sensor, and is proportional to a current flowing through a magnetizing inductor of the winding. Therefore, the current is controlled by modifying a duty cycle of a switch transistor on a bridge arm in the circuit, so that a direct current component of a current flowing through the winding is modified indirectly, thereby avoiding magnetic bias on the magnetizing inductor of the transformer module, and preventing the transformer module from being saturated.

Abstract: A micro inverter and a modulation method thereof are provided in the present disclosure. The micro inverter includes a filter, a transformer, and a switching circuit. The switching circuit includes one or more first switching circuit and one second switching circuit. Each of the first switching circuits has an input terminal serving as an output terminal of a direct-current power supply, and is configured to convert a direct current into an alternating current and output the alternating current to the second switching circuit. An output terminal of the second switching circuit is connected to a primary side of the transformer. A secondary side of the transformer is connected to an input terminal of the filter.

Abstract: A shutdown device for a photovoltaic module, an inverter, a rapid shutdown system, and a method for starting the rapid shutdown system are provided. The method is applied to the rapid shutdown system after each shutdown device in the rapid shutdown system initially starts. The shutdown device is switched into a mode of unlimited output in response to its success in initially starting. The shutdown device, in response to its failure to initially start or when being switched off, samples an electrical parameter at its output terminal in real time, determines whether the electrical parameter meets a preset starting condition, and switches itself on and operates in the mode of unlimited output when the electrical parameter already meets the preset starting condition.